Process for producing powdered metal



v Patented Sept. 19, 1950 I PROCESS FOR PRODUCING POWDERED METAL George R. Smith, Los Angeles, Calif., assignor of five per cent to George D. Todd, Jr., and fortyfive per cent to Walter S. Lindley N Drawing. Application J une 2, 1947, Serial N 0. 751,996

3 Claims. (Cl. 75-05) My invention relates to the production of powdered metal, the primary object being to automatically reduce various kinds of base and noble metals to finely powdered or disintegrated condition suitable for painting, dusting or coating structures, horticultural growth or other surfaces, and in the formation of various objects.

' The invention employs any solid metal to be powdered and a carbide from which gas is released when slacked by contact with an oxidizing agent such as water, in such manner as to disintegrate the metal into finely divided particles.

In the practice of my invention any base or noble metal it is desired to disintegrate is first reduced to molten condition by heating at a melting temperature in a closed receptacle or crucible. Any well known carbide capable of generating acetylene or other gases when slacked is next thoroughly mixed with the molten metal in the receptacle or crucible. The mixture is then spread onto a surface where it is free to congeal and cool. The batch of mixture is then subjected to the effect of an oxidizing agent such as water or other fluid, which is sprayed or otherwise applied, and which slacks the carbide and causes the mixture to disintegrate into finely divided particles of the solid metal of substantially even consistency. Any light weight residue resulting from slacking the carbide is easily blown or washed away leaving substantially an evenly graded metallic ipowder. If desired the metal powder can be finely graded by sifting or air floating to any fineness desired for any use to which the metal powder is applied. During the slacking step gas is generated which is available i'or any use desired. This gas when calcium carbide is employed in the process is acetylene.

An example of my improved process is as follows:

Five parts by weight of aluminum are reduced to molten condition in a closed crucible at its melting temperature. Calcium carbide is also disintegrated into fine particles by grinding or crushing, which may if desired be graded by a screen or other suitable means to remove any relatively coarse granules. Approximately one part by weight of disintegrated and graded calcium carbide is added to the molten metal in the crucible and thoroughly mixed by teeming, that is by pouring the batch of metal and carbide back and forth between ladles, or by stirring or other suitable means for a period of approximately minutes, or until the two ingredients are caused to thoroughly commingle and the surfaces of the metal become coated with carbide and in part form an alloy therewith. The mixture is next poured onto and allowed to spread evenly in a thin layer on a suitable slab or other surface, whereupon it congeals and cools. Water at any suitable or desired temperature is next sprayed or poured onto the batch of mixed metal and carbide, which causes the solid metal which is saturated with carbide to disintegrate and slack into finely divided particles or powder which can be gathered and used for any desired purpose for which metal dust is adapted. The powder resulting from slacking the mixture by contact with water or any other oxidizing medium may be further refined by separating the lime and carbon deposit resulting from slacking the carbide through a blowing, washing or jigging operation.

It is contemplated that the acetylene or other gas which is generated during the slacking step of the process described above may be collected and used for any useful purpose desired.

The invention is equally applicable for disintegrating any desired kind of solid metal and for the production of metal dust of any type. Also it is contemplated within the spirit of the invention to use any type of carbide which is capable of generating gas through water or air slackmg.

Further modification of the invention is contemplated within the spirit of the invention and the scope of the following claims.

I claim:

1. A method of converting powderable solid metals to powdered condition which comprises melting said solid metal, thoroughly admixing with said molten metal a finely ground carbide capable of generating gas upon contact with Water, allowing said admixture to cool and congeal and then treating the admixture with water, said carbide being of a character permitting and being present in an amount sufiicient to cause adequate gas generation to reduce the metal to a powder.

2. A method for converting aluminum to powdered condition which comprises melting said aluminum, thoroughly admixing with said molten aluminum finel ground calcium carbide, allowing said admixture to cool and congeal and then treating the admixture with water, said calcium carbide being present in an amount sufficient to cause adequate acetylene generation to reduce the aluminum to a powder.

3. A method for converting aluminum to powdered condition which comprises melting approximately five parts by weight of aluminum,

thoroughly admixing with said molten aluminum approximately one part by weight of finely ground calcium carbide, allowing said admixture to cool and congeal and then treating the admixture with water.

GEORGE R. SNH'IH.

REFERENCES CITED The following references are of record in the file 0! this patent:

UNITED STATES PATENTS Name Date Stern Nov. 24, 1942 OTHER REFERENCES Comprehensive Treatise on Inorganic and Theoretical Chemistry" by Mellor, v01. 5, published by Longmans, Green 8: Co., 1924, page 864.

Number 

1. A METHOD OF CONVERTING POWDERABLE SOLID METALS TO POWDERED CONDITION WHICH COMPRISESMELTING SAID SOLID METAL, THOROUGHLY ADMIXING WITH SAID MOLTEN METAL A FINELY GROUND CARBIDS CAPABLE OF GENERATING GAS UPON CONTACT WITH WATER, ALLOWING SAID ADMIXTURE TO COOL AND CONGEAL AND THEN TREATING THE ADMIXTURE WITH WATER, SAID CARBIDE BEING OF A CHARACTER PERMITTING AND BEING PRESENT IN AN AMOUNT SUFFICIENT TO CAUSE ADEQUATE GAS GENERATION TO REDUCE THE METAL TO A POWDER. 